Free Claude Code skills for code review and debugging
These are free, open SKILL.md skills for the everyday dev loop: reviewing a diff, turning a vague bug report into a ticket, and figuring out what a stack trace actually means. They work in Claude Code and in Cursor, and you can read every line before you install them.
The skills
Code Review Companion
Paste a diff or snippet and get a structured review in four steps:
- Bugs: logic errors, typos, off-by-ones, wrong comparisons, each quoted
- Edge cases: null/undefined, empty collections, zero, negatives, unexpected types
- Naming and clarity: confusing names or conditions, with clearer alternatives
- The one fix that matters: the single issue that should block merge, and why
Bug Report Triage
Turns "it's broken when I click save" into clear repro steps, a likely root-cause area, a severity call, and a list of what info is still missing. Ready to paste into a ticket.
Error Message Explainer
Paste a confusing error or stack trace. You get a plain-English explanation, the most likely cause, and the first thing to try.
Non-code skills developers use too
- Deep Research Brief: for "should we use X or Y?" questions, with confidence levels and the strongest counterargument
- Meeting Notes → Action Plan: standup or planning notes into decisions, owners, deadlines, and a follow-up message
Install in Claude Code
All five are in the public free-skills repo. Option 1 is to add it as a plugin marketplace:
/plugin marketplace add tyelf22/free-skills
/plugin install skillvize-free-skills@skillvize-free-skills
Option 2 is to copy the folders yourself:
git clone https://github.com/tyelf22/free-skills.git
mkdir -p ~/.claude/skills
cp -r free-skills/*/ ~/.claude/skills/
For one project only, copy them into that repo's .claude/skills/ and commit, so your teammates get them too.
Install in Cursor
git clone https://github.com/tyelf22/free-skills.git
mkdir -p .cursor/skills
cp -r free-skills/*/ .cursor/skills/
Cursor also reads .claude/skills/, so a repo set up for Claude Code works in Cursor as-is. Wondering how this differs from .mdc rules? See Cursor rules vs Claude skills.
Using them
Ask naturally ("review this diff", "what does this error mean?") and the agent picks the matching skill from its description. You can also invoke one directly, for example /code-review-companion.
These are deliberately small, general skills. They don't know your stack's conventions. For that, fork one and add your rules. It's just markdown. (What's in a SKILL.md file?)
Built a better one?
If you've written a skill for your framework or workflow that other developers would want, you can list it on Skillvize, free or paid (up to $100, and you keep 85%).